1. Field of the Invention
This invention relates generally to a device and method for preparing an endoscope instrument for use in medical procedures, and more particularly, to an apparatus and method for preheating an endoscope instrument, such as a laparoscope, thoracoscope, or arthroscope, prior to its use in a medical procedure.
2. Description of the Prior Art
Endoscopy is a surgical technique whereby a thin, fiber optic telescope (endoscope) is utilized to look inside the body cavity of a patient for diagnostic and therapeutic treatment. Examples of procedures that may be done endoscopically include laparoscopic cholecystectomies (gall bladder), laparoscopic appendectomies, laparoscopic colon resections, laparoscopic hernia repairs, laparoscopic hysterectomies, laparoscopic gynecological surgeries, and laparoscopic diskectomies. Other endoscopic techniques include arthroscopy, a procedure to diagnose and treat problems of the joints with a telescope, and thoracoscopy, a procedure for performing chest surgery with a telescope. As experience in the medical field increases, more of these types of procedures are being developed and accomplished with the endoscopic technique.
The first human endoscopic procedure was performed in 1910 by the Swedish physician Jacobaeus. Modern endoscopy procedures began in the early 1960s when the first fiber optic instruments were introduced. In the last ten years, endoscopy (laparoscopy, thoracoscopy, and arthroscopy) has come to the forefront of surgery with millions of these surgeries being performed each year. In fact, technological advances, such as computer aided video cameras and increasingly sophisticated endoscopic instrumentation, has revolutionized the field of surgery by allowing more procedures to be performed endoscopically. Despite its celebrated success, endoscopic surgery has been plagued with a persistent problem. Since its inception, the most common problem encountered in endoscopic surgery is fogging of the telescope lens. Although scope fogging ranks low in terms of severity on the overall scale of potential problems that can occur, it is still a nagging problem which occurs in almost all procedures. Fogging occurs when the endoscope, which is at room temperature (usually 70.degree. to 80.degree. F.) is introduced into the warm (98.6.degree. F.), moist environment of the abdomen, joint space, or other body cavity. This problem is analogous to the fogging on a car window on a cold day or on a bathroom mirror during a shower.
Techniques for dealing with fogging have been around as long as the scopes, but no single answer has adequately addressed the problem. All attempts at prevention have been aimed at thwarting the basic environmental fact, i.e., a cold piece of glass placed in a wet, warm environment will fog. Methods commonly used to prevent endoscopic fogging have included warming the endoscope or chemically treating the endoscope lenses. An anti-fog chemical, such as Endo-Fog.TM. or F.R.E.D..TM., has been used to chemically treat the endoscope lens prior to use to prevent fogging. Warming the endoscope has been done by wrapping it in a warm, moist towel or soaking it in warm saline prior to its use.
These anti-fogging methods, however, are unreliable. Anti-fog chemicals typically require several applications which necessitates removal from the body allowing the scope to cool. Using warm towels or saline solutions to prevent lens fogging is also undesirable. First, the towels rapidly cool down in the low temperature environment of the operating room. Second, in certain procedures, such as a cholecystectomy, the endoscope must be removed several times from the patient, so fresh, warm towels or saline solution must always be readily available. Third, warming solutions are often kept in a bowl-like dish which may easily be knocked over damaging the endoscope. Finally, it is difficult to maintain the scope at a constant temperature and to keep the endoscope sterilized with these noted warming procedures.
There is also a device known in the background art which provides a sheath as an alternative to warming an endoscope prior to use. However, this device does not adequately solve the above noted problems. Brodsky, in U.S. Pat. No. 5,351,675, discloses a casing for preheating an optical instrument prior to use. The casing comprises an outer sleeve and an inner sleeve which includes first and second chemicals, respectively. These chemicals are mixable for producing an exothermic chemical reaction when disturbed in order to heat the sleeve and warm the laparoscopic instrument when it is received in the sleeve assembly. The heat is produced when a first envelope containing one of the chemicals is ruptured inside another envelope containing the other reactive chemical. The resulting chemical reaction produces the heat until the reaction is complete. This device is considered complicated in design, as it relies on an exothermic chemical reaction to produce heat. While this chemical reaction initially produces the necessary heat, the chemical reaction gradually subsides, especially in a lengthy surgical procedure, incrementally reducing in temperature until the sleeve is completely cooled. In addition, the chemical reaction can potentially harm a patient, cause some type of allergic reaction, burn the patient, or cause other side effects if the sleeve should leak.
Several other sheaths are contemplated in the background art, however, these sheaths do not address the concerns associated with lens fogging. Rather, they provide sheaths for insulating sterilized scopes or for cleaning the scope while it remains in the body. For example, U.S. Pat. Nos. 5,237,984 and 5,413,092, issued to Williams, III et al., and U.S. Pat. No. 4,741,326, issued to Sidall et al., provide a barrier between a non-sterile telescope and the patient's body cavity so as to eliminate the time consuming and expensive sterilization process required between uses of the endoscope. Plastic sheaths are disclosed in U.S. Pat. Nos. 5,207,213, issued to Auhil et al.; 5,313,934, issued to Wiita et al.; 5,400,767, issued to Murdoch; and 5,392,766, issued to Masterson et al., and comprise enclosures for telescopic instruments which facilitate in-the-body cleansing of a smudged lens, so that the scope may remain inside the patient.
The above-noted background art neither solves nor addresses the problems contemplated by the present invention. The devices known do not provide a warming device capable of controllably maintaining a constant temperature (body-like or otherwise) for an unlimited duration to prevent the well known problem of lens fogging associated with endoscopic surgery. In addition, some of the background devices can place the patient at risk of injury. Accordingly, there remains a need for a device capable of safely preheating an endoscopic instrument prior to use and heating it at intervals during its use so as to prevent lens fogging, a problem which has been around since the inception of endoscopic technology. The present invention solves these problems by providing an endoscope warming holster which conveniently, controllably and indefinitely maintains an endoscope at body temperature without the noted risk and drawbacks. While the endoscope warming holster is described in detail below with respect to endoscopes, the warming holster works for varying the temperature of any surgical instrument which requires preheating prior to use.